I don't know why, but I keep damaged or other cool looking coins. Like if I find a bent quarter, chipped penny, or some other type of damage to coins I'll keep them. I have one quarter that's completely coated in bright red paint.
Retro games from almost all systems even though they're all in boxes. I plan on setting them up and never playing them eventually.
Various virtual collections, if those count? Pokemon. Any free games from Prime Gaming, Epic Games, etc. Lately, cute decor Pikmin in Pikmin Bloom. That's been keeping me out walking a lot and getting healthier, so that's a fun one.
My partner collects enamel pins (and gifts me ones she thinks I'll like, so I have a tiny collection of those from her). She also collects wood puzzles (like 3D models), those metal brain teaser puzzles, and dice.
I'm sure I'm missing a few others but that's all I can think of for now.
I've never used an app to track, but as a teen my periods were so inconsistent that they would probably think I was pregnant and miscarrying every 3 months. There were times I didn't bleed for 3 months then bled for 2, for years. This led me to starting birth control years before I ever had sex for the first time. I definitely would have been on some watchlist if that took place today.
Luckily, after years of trying to stop birth control (and going right back into that weird bleeding cycle every time! >:[ wtf body) my new doctor agreed to do a hysterectomy! It was just recently done, so I'm still recovering, but I'm so fucking happy I never have to deal with periods and bc pills ever again!
Sorry for the novel lol